European Heart Journal Advance Access published online on October 23, 2009
European Heart Journal, doi:10.1093/eurheartj/ehp428
Do systemic risk factors impact invasive findings from virtual histology? Insights from the international virtual histology registry
1 Department of Cardiology, Westgerman Heart Center Essen, University Duisburg-Essen, Hufelandstr. 55, D-45122 Essen, Germany
2 Department of Cardiology, Cardiovascular Centre, Aalst, Belgium
3 Mid America Heart Institute, Saint Luke's Hospital, Kansas City, MO, USA
4 Minneapolis Heart Institute and Foundation, Minneapolis, MN, USA
5 Division of Cardiology, Department of Medicine, Medizinische Klinik und Poliklinik-Innenstadt, Munich, Germany
6 Division of Cardiovascular Diseases, Mayo Clinic College of Medicine, Rochester, MN, USA
7 Erasmus Medical Center, Thoraxcenter, Rotterdam, The Netherlands
Received 13 March 2009; revised 16 July 2009; accepted 20 August 2009 * Corresponding author. Tel: +49 201 7234805, Fax: +49 201 7235484, Email: sebastian.philipp{at}uk-essen.de
Aims: Cardiovascular risk factors such as elevated serum lipid levels are important in the development of coronary atherosclerosis. Radiofrequency (RF) analysis of intravascular ultrasound [IVUS, Virtual histologyTM (VH)] offers a unique tool to study the composition of coronary atherosclerotic plaque in vivo. We used data from the multicentre VH registry to assess the association between cardiovascular risk factors and coronary plaque volume and composition.
Methods and results: Between August 2004 and July 2006, 990 patients in 42 centres were enrolled in a prospective, multicentre, non-randomized global VH registry. Coronary artery imaging was performed by conventional IVUS and RF-IVUS. The four RF-IVUS plaque components [dense calcium (DC), necrotic core (NC), fibrous (F) tissue, and fibro fatty (FF)] were analysed in every recorded frame. The results were expressed as mean cross-sectional areas, absolute volume, and percentage of total plaque volume. Risk factor assessment included evaluation of family history of previous myocardial infarction (MI), past or current smoking, diabetes mellitus, hypertension, and the laboratory measurements. Patients with diabetes had an increased relative proportion of NC (6.47 ± 0.28 vs. 5.86 ± 0.14%, P = 0.037) and DC (4.58 ± 0.27 vs. 3.90 ± 0.14%, P = 0.017), and patients with hypertension had an increased relative proportion of FF, DC (4.35 ± 0.16 vs. 3.57 ± 0.17%, P = 0.02) and NC (6.24 ± 0.17 vs. 5.60 ± 0.19%, P = 0.01). Compared with patients with LDL-C <100 mg/dL, patients with LDL-C >160 mg/dL had higher plaque volume (342.1 ± 26.2 vs. 318.6 ± 10.7 mm3). Linear regression analysis showed a correlation between the level of HDL-C and F (r = –0.149, P < 0.01), FF (r = –0.106, P < 0.01), and NC (r = –0.90, P < 0.05). The level of LDL correlated with F (r = 0.110, P < 0.01). Patients with prior MI have an increased percentage of F (30.03 ± 0.59 vs. 28.20 ± 0.37%, P = 0.009). Smoking had no relevant effect on plaque composition. Treatment with acetylsalicylacid and statins reduced FF with altering plaque volume.
Conclusion: Radiofrequency-IVUS detects marked differences in coronary plaque composition related to the risk factor profile with particular focus on lipid levels. Greater amounts of NC were associated with diabetes, hypertension, MI, and low HDL-C. The effects of treatment of changes related to plaque composition are underway.
Key Words: Intravascular ultrasound • Radiofrequency • Virtual histology • Plaque composition • Risk factors
The authors contributed equally to this work.